Description Usage Arguments Details Value Methods Author(s) See Also Examples
It is not necessary to understand this help page if one merely wants to estimate a factor analysis model. This help page is intended for those who want to modify or extend FAiR or otherwise want some idea of how FAiR works “behind the scenes”.
Factanal
is just a wrapper around a call to
genoud
in the rgenoud package. These S4
generic functions are passed to various arguments of
genoud
as part of the optimization process. With
the exception of the methods for create_start
, it would be very
unusual for any of these methods to be called directly by the user.
1 2 3 4 5 6 7 8 9 10 | ## S4 method for signature 'restrictions,manifest.basic'
fitS4(par, restrictions, manifest, lower, mapping_rule)
## S4 method for signature 'restrictions,manifest.basic'
bfgs_fitS4(par, restrictions, manifest, helper, lower)
## S4 method for signature 'restrictions,manifest.basic'
gr_fitS4(par, restrictions, manifest, helper, lower)
## S4 method for signature 'restrictions,manifest.basic'
bfgs_helpS4(initial, restrictions, manifest, done, lower)
## S4 method for signature 'restrictions,manifest.basic'
create_start(number, start, restrictions, manifest, reject)
|
par |
A numeric vector containing values for all the free parameters
to be estimated, which corresponds to the |
initial |
Same as |
restrictions |
An object of |
manifest |
An object of |
lower |
A small numeric scalar indicating the lower bound for positive
definiteness or minimum uniqueness; see the corresponding argument
to |
mapping\_rule |
a logical indicating whether to invoke the mapping rule in
semi-exploratory models. It takes the value of |
helper |
A list that contains necessary information for the |
done |
A logical indicating whether the optimization has terminated
or could terminate immediately if a stopping condition is met; see the
documentation of the |
number |
An integer representing the number of starting values to create |
start |
A numeric vector or matrix containing initial communality estimates |
reject |
Logical indicating whether to reject starting values that fail the constraints required by the model |
... |
Further arguments to be passed to downstream functions; not currently used. |
The fitS4
method is responsible for producing a complete numeric vector of
fit criteria and is passed to the fn
argument of genoud
.
The default method simply calls restrictions2model
and then calls an internal
function that evaluates all the functions in the criteria
slot of the object of
restrictions-class
.
The bfgs_fitS4
method produces a scalar fit criterion, and this
method is passed to the BFGSfn
argument of genoud
and is in turned passed to the fn
argument of optim
. Usually,
this criterion is the last criterion produced by the fitS4
method, which is the
discrepancy function. The gr_fitS4
method produces the gradient
of the function defined by the bfgs_fitS4
method under traditional maximum
likelihood estimation; otherwise it is an internal function. Either way, this function
is passed to the gr
argument of genoud
and
optim
. Both bfgs_fitS4
and gr_fitS4
take an
argument called helper
, which is produced by the bfgs_helpS4
method and corresponds to the BFGShelp
argument of
genoud
. The BFGShelp
method produces a list
that contains information about the initial value of the genetic individual
when optim
is called. The bfgs_fitS4
methods and gr_fitS4
methods can behave differently depending on the contents of helper
.
The create_start
method creates a matrix of starting values that is
then passed to the starting.values
argument of
genoud
. If you think the starting values are inadequate
in a particular situation, it is much easier to create a matrix of starting
values in the global environment and pass it through the ...
of
Factanal
to the starting.values
argument of
genoud
yourself. See Factanal
for details
on doing so.
fitS4 |
produces a numeric vector of fits |
bfgs_fitS4 |
produces a numeric scalar as a fit |
gr_fitS4 |
produces a numeric vector that is the gradient at the scalar fit |
bfgs_helpS4 |
produces a list of ancillary material for |
create_start |
produces a numeric matrix that constitutes the starting population |
There are methods for every flavor of restrictions-class
, although in
many cases the methods are simply inherited. Currently, there are only methods for
objects of class "manifest.basic"
, which are inherited by objects of class
"manifest.data"
and "manifest.data.mcd"
. However, it is possible to
tailor methods for different flavors of manifest-class
or to create
new classes that inherit from restrictions-class
and write (some)
methods for them.
Ben Goodrich
Factanal
, manifest-class
, restrictions-class
and
genoud
1 2 3 4 5 | showMethods("fitS4")
showMethods("bfgs_fitS4")
showMethods("gr_fitS4")
showMethods("bfgs_helpS4")
showMethods("create_start")
|
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.